Electrical weft detector for looms



Dec. 1, 1931 v MacARTHUR 1,834,315

ELECTRICAL WEFT DETECTOR FOR LOOMS Filed Dec. 2. 1929 fv VENTUF? 5/.\///\/U /\7ACAA THUR A 77'C7FPNE Y5 Patented Dec. 1, 1931 msme PATENToFFicr:

'ELVIN D. MACARTHUR, OF OLD HICKORY, TENNESSEE, ASS IGNOR TO CROMPT'ON &

KNOXN'LES LOOM WORKS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS A neation filed December 2, 1929. Serial No. 410,901.

current conducting support for the weft boblow shuttle fitted over itand heldthereto fricbin or cop. I r

Certain forms of shuttles are provided with metallic spindles whichsupport a hol tionally. It is an important object of my presentinvention to provide positively and negatively charged yarn contactingelements which upon occurrence of substantial exhaustion of weft mayhave electric contact with the spindle to close a circuit external tothe shuttle and efiective to produce a change in the operation of theloom.

In the type of shuttle referred to it-is common to employ paper tubes onwhich the weft is wound, and it is a further object of my presentinvention to perforate such a tube at a plurality of points toCOOPGIatflWlth groups of plungers or needles, the perforations to beuncovered at weft exhaustion to permit the needles to pass therethroughand have direct contact with the metallic spindle.

It is common experience that a shuttle will rebound slightly so that itis not always possible to forecast its exactlooation at the time thedetector cooperates with it, and it is a further object of my inventionto arrange the perforations in such a way that one or an other of thecontacting plungers or needles will always be in position to passthrough a perforation irrespective of the location ofthe shuttle,throughout at least a limited range of displacement. The object in usingthe perforations is to preserve thestrength of the paper tube whichcould'not be done if a rela tively long slot were cut therein.

It is a further object of my inventionto provide a weft detectordepending-for its operation upon the entry of one or more plungers intoperforations formed in the weft carrier and wherein the arrangement issuch that misplacement of the shuttle will not interfere with theoperation of the detector and wherein at the same time the-bobbinisprovided with comparatively small openings which do not materiallyweaken it.

ELECTRICAL warm DETECTOR FOR Looms With these and other objects in viewwhich will appear as the description proceeds my invention resides inthe combination and ar-' rangement of parts hereinafter described andset forth in the claims.

In the accompanying drawings, wherein two forms of the invention areshown,

Fig. 1 is a top plan view of a shuttle having a weft carrying cop madeaccording to the preferred form of my present invention and showing thesame cooperating with my improved detector,

Fig. 2 is a vertical section on line 2-2 of Fig. 1-, f

Fig. 3 is an enlarged vertical section takcn online 33, and

1 Fig. 4; is a view similar to Fig. 1 but showing a modified arrangementof perforations with respect to the plunger.

Referring to Fig. 1, I have provided the lay L with a binder B to engagethe front wall of a shuttle S. The latter is held against the box back10 by means of the binder and the shuttle may be propelled by the picker11.

The shuttle may be provided with a metallic spindle 12 having a butt 13pivoted to the body of the shutle and having a tongue 14 to enter a slot15 formed in the paper tube 16. The latter is provided with an internaltaper substantially equal to the external taper of the spindle and isforced on the latter to be held thereto by friction, the tongue 14entering the slot 15 so as to determine the angulardle 12 beingaccessible through the perforations 20.

The weft detecting element comprises a fixed bracket 22 having ahorizontal platform 23 on which are mounted plates 24; and 25 insulatedfrom the platform. The plate 24 has upstanding spaced rear and forwardbearings 26 and 27, respectively, while the plate 25 is provided in asimilar manner with upstanding rear and forward bearings 28 and 29,respectively. The bearing 27 may be connected to a wire 30 while thebearing 29 may likewise be connected to a wire 31.

Slidably mounted in bearings 26 and 27 are equally spaced detectorelements in the form of metallic plungers or needles 32 which may beformed of rods or wires each of which is provided with a shoulder 33.Each detector element 32 is provided with a compression spring 3%interposed between its shoulder and the front bearing plate 27'.

Similarly the negative side of the circuit is connected to plungers 35which have shoulders 36 to receive the rearward thrust of springs 3?bearing against the front plate 29. It is to be understood that theconstruction is a 11 that wire 30 is in electrical contact with all ofthe plungers 32 while wire 31, is connected electrically to the plungers35.

By referring to Fig. 1 it will be seen that the distance between theperforations 20 is difiierent from and in this instance greater than thedistance between the individual de tector elements 32 of the positivegroup, and this same relation exists also with respect to the other setof negative detector elements 35.,

In operation of the preferred form, when sufficient weft is present, allof the, plungers or detector elements 32 and 35 will be pressedforwardly against their springs by the yarn on the tube and will be outofcontact with the spindle 12, but as exhaustion approaches theperforations 20 will be uncovered so that at least one of the elements32 and one of the elements 35 will be able to have electrical contactwith the spindle 12. In this way the wires 30 and 31 are electricallyconnected and the external circuit not shown but well understood will berendered effective to cause stopping the loom or weft replenishment.

As shown in Fig. 1 the shuttle is properly placed so that he left handdetector of each group located opposite a perforation 20. Should theshuttle rebound, however, so as to be misplaced slightly to the left,then the central detector of each group will be opposite a perforation20. hen the displacement is greater, the right hand detector of eachgroup will be in ali nment with a perforation. This result is achievedby making the interval between the perforations different from theinterval between the detector elements. In this way I am able topreserve substantially the original strength of the tube by usingcomparatively small perforations and at the same time provide for acertairr limited amount of displacement of the shuttle.

In the modified form of the invention shown in l the interval betweenthe perforations 40- are substantially equal to the interval betweenadjacent detectors of a group, this arrangement affording more than oneopportunity for each side of the circuit to have contact with thespindle. WVith this latter arrangementif a single stray strand offilling should happen to be in the path of one detector element eventhough exhaustion is imminent, yet one or another of the elements canhave contact with the spindle and thereby bring about, a change in theoperation of the loom. In the modified form the detector may occupy thesame position it has in the preferred form, but the location of theholes in the copwill be different.

From the foregoing it will be seen that I have provided a simple form ofelectrical weft detector wherein a metallic spindle is used and where apaper tube or other form of hollow spindle is provided. with a pluralityof comparatively small perforations which do not materially lessen itsstrength. In one instance the interval between the perforations measuredlongitudinally of the shuttle is different from that between thedetector rods so as to provide for a certain amount of shuttlemisplacement, whereas in the other form of the invention this intervalis. the same for the detector rods so that each side of the circuit hasa plurality of opportunities to establish contact with the spindle.

Furthermore, it will be seen that I have provided a broader sense a weftdetector operating on the principleof a plunger enterlng a weft. carrierwherein the latter is not materially weakened but wherein throughout alimited range of misplacement oneor another of a. group of plungers maybe effective to enter the carrier to effect. indication.v In this latterregard I do not consider that my invention is necessarily limited toanelectrical. detector.

Having thus described my invention it will be. seen that changes: andmodifications may be made therein by those skilled in the artwithoutdeparting from the spirit and scope of the. invention and I do not wishto be limited to thedetails herein disclosed, but what I claim is:

1.. In an electrical weft detecting mechanism to cooperatewith ashuttle.- having a metallic spindle, two groups of aligned separatelymovable electric current conducting detector elements, and. a weftcarrier of insulating mate-rial having a single row of aligned openingsextending longitudinally of the. carrier, there being one. opening foreach detector element, the distance between adjacent elements of a.group being slightly different from the distance between adjacentcorresponding openings in the carrier meas ured a directionparallel tothe spindle.

2. Inan electrical weft detecting mechanismto cooperate with a shuttlehaving a metallic spindle,two. groups of aligned separately movableelectric current conducting detector elements, and a weft carrierofinsulating material having a single row of aligned openings extendinglongitudinally of the carrier, there being one opening for each detectorelement, the distance between adjacent elements of a group beingslightly difierent from the distance between adjacent correspondingopenings in the carrier measured in a direction parallel to the spindle,the distance between corresponding elements in the groups being equal tothedistance between their corresponding openings.

3. In an electrical weft detecting mechanism to cooperate with a shuttlehaving a. metallic spindle, two groups of aligned separately movableelectric current conducting detector elements, the elements of a groupbeing equally spaced, and a weft carrier of insulating material having asingle row of aligned openings extending longitudinally of the carrier,there being one opening for each detector element, the openings beingequally spaced, the distance between adjacent elements of a group beingslightly different from the distance between adjacent correspondingopenings in the carrier measured in a direction parallel to the spindle.

4. In an electrical weft detecting mechanism to cooperate with a shuttlehaving a metallic spindle, two groups of aligned separately movableelectric current conducting detector elements, the groups beinginsulated from each other and the elements of a group being equallyspaced and the groups being spaced apart more than the distance betweenadjacent elements of a group, and a weft carrier of insulating materialon the spindle having a single row of equally spaced holes arrangedlongitudinally of the spindle, the distance between adjacent holes beingslightly greater than the distance between the centers of adjacentdetector elements in the same group but substantially less than twicesaid distance.

In testimony whereof I have hereunto affixed my signature.

ELVIN D. MAOARTHUR.

